Field of the Invention
The present invention relates to an image forming apparatus, for example, a copying machine or a printer.
Description of the Related Art
An image forming apparatus performs processing for improving image quality after completion of a warm-up process upon startup, for example. For example, the image forming apparatus forms a particular pattern, for example, a gradation pattern, on a recording material, for example, paper, and reads the particular pattern by an image reading apparatus, for example, a scanner. The image forming apparatus feeds back information in accordance with the read particular pattern to image forming conditions, such as a gradation correction value.
The image forming apparatus needs to maintain highly accurate image density characteristics stably for a long time. In this case, the image forming apparatus reads the gradation pattern formed on the recording material, and generates a gradation correction table based on information in accordance with the read gradation pattern. The image forming apparatus stores densities of the gradation pattern formed on a photosensitive member using the generated gradation correction table, and adjusts the gradation correction table at a predetermined timing depending on a relationship between densities of an image formed on the photosensitive member and the stored densities (U.S. Pat. No. 6,418,281).
However, the detected densities of the particular pattern, for example, the gradation pattern formed on an image bearing member, for example, the photosensitive member, and the image densities of the particular pattern formed on the recording material do not match. Therefore, after the gradation correction table is generated based on the particular pattern formed on the recording material, there is a need to form the same particular pattern again on the image bearing member to obtain target densities of the particular pattern, and the processing takes time. This may cause a reduction in efficiency of the image forming processing. To address this problem, it is an object of the present invention to provide an image forming apparatus with increased efficiency of processing for maintaining stability of image density characteristics.